Railway-traffic-controlling apparatus



Mar. 3. 1925.

l3.v E. O HAGAN' RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Anal. 8, 1924 INVENTORI BY Q- x-fmz 7 1 1 4. ATTORNEY Patented Mar. 3, 1925.

BERNARD E. OHAG ANfOF SWISSVAILE; PENNSYLVA I ,*assIGNoRTo *"Uiiioiq SWITCH & SIGNAL "COMPANY, or swrssvann', PENNSYLVANIA,A 'CORPORATIdN OF PENNSYLVAN mnwsmmw'm'comnbmim APPARA'i iIsf Be'it known "that I, BERnA'RD OI-IAoma,

a citizen of the-Uni'tedstates;residing at 5 State of Peniisylv'aniaf have invented cer tain new'and useful"Improvementsin Rail- Way-T1"afiic-Controlling Apparatus, of which" thefoll'oiving is specification.

1 con-trollin 'appai atus, ancl particularly to apparatus of the type; cofnbrising" tlfain cai ried"goi eining means con olled by energy received-from "thetracktta More particularly my invention i'elate's to the trackwdy portionof suchepparatusj t I I will described one form "and" arrangement of railway trafiic controlling apparatus embodying" lnyintention, and will? then point out the" novel" features thereof in claims.

The accompanying:drawingis a diagrammatidviewshowing one form of trackway apparatus embodying in y "invention. Referring'to this drawing; i the reference characters 1 andl designate thetrack rails of a stretch "of ra'ilw ay track over which traffic normally moves in thedirection of the arrow: These track rails" are divided, by

means ofinsul'atedoints"2 into a plurality signals have been omitted from thedrawing for thesali'e of simplicity. v

SectionsAB' is provided with a track 21. One Winding 20 isconstan'tly supplied with alteniating currentfroin some -suitable source, such as an alternator"Mfover' lin'e Wires 6 and 6 this relay is const antlfy' connected across" the rails adjacent the "entrance 'end of the section. The track relay may be used to con trol train""governing ineans, not shown 'in" the 'drawingf in' any "desiredfina'nnei." Sec tion is'further provided with a track transforme'rT" havihg a secondary '3 con-' stantly connected across thc'"rai'ls adjacent the end of: the section An il npedance fi is'interposed between secondarys of tranS- and since they form no part of the 'pr'e'sent' relay R comprisingtwo windings 20 and The other Winding; 21, of

former T and one rail, lfofthe 'fassociatfed section in the usualfin'afine a id thejariina-i'y I v v 5 of transformenT 1S constai Swiss'vale, in the countybf Allegheny and."

with alternating current front line Wires 6 and 6 The 'trackway"apparatus her suitable for controlling train carri'e tl'gm e ing apparatus resjionsive to" the "jaresencebi alternatingcurrent injthef track ail'sfial'id I f this control is, jin certain systems," effected" I." J13 a e: an through the-inedluinj of re ;e1v1n 1p 1 '65 has carried "in advance of the ifoiwt ai'd a xle of the trainz In such "systems? it will f seen that the source 'of alteii atiirg current? must be connected mess tl1era'i1s in ad- Vance of the train. 7 l H V In some instances, however, "it is"desirable to: connect the track transformer "aeros s the" rails at the entrance end of a sectibn'. One exaniple'ofsuchan in's'tanceis shown. in see, tioir'B C. This sectionis ,cut? by being 7 dividedfby menis i insulated joi nts*2 at QOlIllZ X into a rear sub' section 13 K and 7 7 I J a forward sub sec'ti'on X-, as for the v pose of controlling a highway cross1ngs1g' nal not shown 1n"the"drdn 1ng but locaite'd at? the"inti"section of therai'lWaY Witl a l highway Q Under these conditions a t1 ck] transfo'ln'iei T is connectedacross the rails adj ec'ent the left hind end of sub seamen BX,*and a "siniila-r-track traiistorinerfT? is connected "across' the rails adjacent the right hand end of sub section X Cf These two. transformers T and T are'constirii'tly supplied With alternating"current'over line I H j a j 3 .icores 6 and 6. Located at point X are two track relays n min each siini'lar to felay R and each having a. Winding" 20- emistmuy connected with line wires b 6. The

Winding 21 of relay R is connected with" 'the' rails adjacent the exit j end of sub, section B-X,"and Winding Q I of rem s is con'-' 'nected across the rails adjacent the entrance end" of sub section X+CI "rantgein ent it will beclear that a train pro gres'sing "through section A -Bj or" sub 1 section XC fin sediments "of tlitaarfbwh will have itsgoverning apparatus supplied through the "associated re'ceiting" app a we with alternating" when from a transformer 'T'connec'tedhcros's the rails in advance o fflos the train, but that a train moving-in this direction through sub section will have the "alternating tracltcurfent "shunted away from the receiving apparatus by the wheels and axles of the train since the source of supply of alternating current for-this sub section is located in rear of the train.

I therefore provide sub section B-J: with an auxiliary transformer II having its secondary 3 connected, through an impedance 4, across the rail adjacent the exit end of sub section B-X. This transformer is so connected that the current supplied thereby to the rails is of an instantaneous relative polarity opposite to that supplied to the rails by transformer T Current from this transformer, therefore, will not pick up relay R", and futhermore, the parts are so proportioned that if sub section BX is unoccupied and transformers T and H are both energized, the currents supplied by these two transformers will neutralize each other in their efiect upon relay R To con trol the supply of current to transformer H I connect a slow acting relay K across the rails adjacent the point of connection of transformer T By slow acting I mean that the relay is so constructed that when the relay is ener ized av considerable interal of time elapses subsequent to the opening of the back contact and prior to the closing of the front contact thereon. The circuit for transformer H may be traced from line wire 6, through wire 7, front contact 8 of relay R wire 9, back contact 10 of relay R wire 11, primary 5 of transformer H, wire 12, front point or back point of contact 13 of relay K, and wire 14 to line Wire 6.

As shown in the drawing the parts are all in the positions corresponding to the unoccupied condition of the stretch of track shown in the drawing. Under these conditions all track transformer T are energized, all track relays R and slow acting relay K are also energized, but the circuit for transformer H is broken at back contact 10 of relay R I will now assume that a train, moving in the direction of the arrow passes through the stretch of track shown in the drawing. As this train proceeds through section AB the governing apparatus on the train receives energy from transformer T toward which the train is proceeding. As the train enters sub section I3I.I, relays K and R become (tie-energized, thus supplying current to transformer II, which in turn supplies alternating current to the rails of the sub section for the control of the train carried governing apparatus. As the train enters sub section X@ the de-energization of relay R interrupts the circuit for transformer H and when the train moves out of sub section BX, the energization of relay R restores the apparatus to normal.

I will now assume that a train moves through the stretch of track shown in the drawing in a direction opposite to that inclicated by the arrow. Relay R will then be tie-energized as the train enters sub section XC. When the train enters sub sec tion B-X, relays K and R become de-energized. lVhen the train clears sub section X-C, the energization of relay R completes the circuit for transformer II but, because of its relative polarity, current from this transformer is ineffective to energize relay I1 and the circuit therefore remains closed for transformer H at back contact 10 of relay R hen the train clears sub sect-ion BX, relay K picks up. Due to the slow acting characteristics of relay K the circuit for transformer H is opened for a time interval and during this interval the supply of alternating current to the rails by transformer II is discontinued. As a result current from transforn'ier T picks up relay R and when the front point of contact 13 finally closes it is not effective to reenergize transforn'ier H because the circuit for this transformer is now open at back contact 10 of relay R hen the train leaves section AB, the energization of relay R returns the apparatus to its normal condition.

As here shown my invention is applied to a cut section arranged to control a highway crossing signal but itshould be pointed out that the invention may be applied to a track circuit under other conditions in which the track transformer is located at the entrance end of the block and it is desired to control train carried governing apparatus by means of current in the track rails.

Although I have herein shown and described only one form and arrangement of trackway circuits embodying my invention, it is understood that various changes and modifications may he made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention,

what I claim is:

1. In combination, a stretch of railway track, a first track transformer connected across the rails adjacent one end of the stretch and constantly supplied with alternating current, a second track transformer having a secondary connected across the rails adjacent the other end of the stretch, a track relay connected across the rails of said stretch and arranged to be operated by current from said first transformer but not by current from the second transformer, a slow acting relay also connected across the rails of the stretch, and means controlled by both said relays for at times supplying said second transformer with alternating current.

2. In combination, a stretch of railway track, a first track transformer connected across the rails adjacent one end of the stretch and constantly supplied with alternating current, a second track transformer having a secondary connected across the rails adjacent the other end of the stretch, a track relay connected across the rails of said stretch and arranged to be operated by current from said first transformer but not by current from the second transformer, a slow acting relay also connected across the rails of the stretch, and means effective when said track relay is de-energized and said slow acting relay is either energized or de-energized for supplying alternating current to said second transformer.

3. In combination, a stretch of railway track, two track transformers one located at each end of the stretch, a track circuit for said stretch including in series the two rails of the stretch and the two secondaries of said transformers, means for constantly sup plying one of the transformers with alternating current, a track relay for said stretch arranged to be picked up when the stretch is unoccupied and said one transformer is energized but to be released when the stretch is unoccupied and both said transformers are energized, means including a back contact of said track relay for energizing the remaining transformer when a train moving in one direction enters the stretch, and means effective when such train leaves the stretch to interrupt the circuit for said second transformer for an interval to cause the track relay to open said back contact.

4:. In combination, a stretch of railway track, two track transformers one located at each end of the stretch, a track circuit for said stretch including in series the two rails of the stretch and the two secondaries of said transformers, means for constantly supplying one of the transformers with alternating current, a track relay for said stretch arranged to be picked up when the stretch is unoccupied and said one transformer is energized but to be released when the stretch is unoccupied and both said transformers are energized, a slow acting relay connected in parallel with said one transformer, and a circuit for supplying alternating current to the other transformer over a back contact of said track relay and a back contact of said slow acting relay, said circuit also including a front contact of the slow acting relay in parallel with the back contact thereon.

5. In combination, a stretch of railway track, means for constantly supplying alternating current to the rails at one end of the stretch, a transformer connected with the rails at the other end of the stretch, means including a first circuit controller and a second circuit controller for at times supplying alternating current to said transformer, means responsive to traffic conditions for at times opening said first circuit controller for an interval of time, and means responsive to such opening of the first circuit controller for opening the second circuit controller to thereby prevent energization of the transformer when said first circuit controller again closes.

6. In combination, a stretch of railway track, a track relay for said section, two transformers one adjacent each end of the stretch and each having its secondary c011- nected with the rails in such manner that when both transformers are energized, said track relay is de-energized, means for constantly supplying one said transformer with alternating current, means including a back contact of said track relay for at times supplying alternating current to the other said transformer, and means for at times temporarily interrupting such supply for a brief interval for the purpose of energizing the track relay whereby the circuit for said other transformer is opened at the back contact of such relay.

7. In combination, a stretch of railway track, means for constantly supplying alternating current to the rails adjacent the entrance end of said stretch, a first track relay connected with the rails adjacent the exit end of said stretch, a second track relay responsive to traffic conditions in advance of said section, a transformer having a second ary connected across the rails adjacent the exit end of the stretch, a slow acting relay connected across the rails adjacent the entrance end of the stretch, and means for supplying alternating current to the primary of said transformer when said slow acting relay is energized or is de-energized provided said first track relay isde-energized and said second track relay is energized.

In testimony whereof I affix my signature.

BERNARD E. OHAGAN. 

